This invention relates to dextranase containing-oral compositions having a good feeling in use.
It is well known, for example, from U.S. Pat. No. 3,686,393 to incorporate dextranase in oral compositions as an active ingredient for caries prophylaxis to prevent the formation of dental plaque.
Unfortunately, dextranase tends to be deactivated by moisture, anionic surfactants and other ingredients in oral compositions. Several approaches have been proposed to stabilize dextranase as disclosed in U.S. Pat. Nos. 3,981,989, 3,991,177, 4,115,546 and 4,140,758 and G.B. Pat. No. 1,427,300.
Japanese Patent Publication No. 50-3378 discloses that a certain flavor is blended with dextranase to stabilize it, the flavor being selected from aliphatic alcohols having 7 to 17 carbon atoms and their esters, terpene hydrocarbones, phenol ethers and lactones.
When oral compositions are used in the mouth, they must have a good feeling in use. Merely blending a certain flavor as mentioned above is, however, insufficient to obtain oral compositions with a good feeling. It is therefore necessary to blend an additional flavor such as carvone, eugenol, methyl salicylate and cinnamic aldehyde to improve the feeling of compositions so as to meet the taste of consumers. However, carvone and similar flavors are believed to adversely affect the stability of dextranase as indicated in Japanese Patent Publication No. 50-3378. A problem still remains in stabilizing dextranase without impairing the feeling of oral compositions.